title: A Double in vivo Biotinylation Technique for Objective Assessment of Aging and Clearance of Mouse Erythrocytes in Blood Circulation.
abstract: We have recently developed a new technique to objectively identify erythrocyte cohorts of defined age in mouse blood. The technique (termed double in vivo biotinylation, DIB) involves an initial biotinylation of all erythrocytes in circulation, followed after a few days by a second biotinylation, at a lower density, that labels the biotin-negative erythrocytes that have entered since the first biotinylation. The proportions of biotin(high), biotin(low), and biotin(negative) erythrocytes are enumerated by flow cytometry. The DIB technique allows us to track age-related changes on erythrocyte cohorts (Protocol A), and to simultaneously identify very young and older erythrocyte populations in the blood (Protocol B). Using this technique, we have reexamined: i) the relationship between age and buoyant density of erythrocytes, ii) erythrocyte destruction through a random removal mechanism, and iii) the expression of phosphatidylserine on aging erythrocytes. We have also used the DIB technique to study age-related changes in the expression of various markers like CD47 and CD147 and green autofluorescence in aging erythrocyte populations.
authors.affiliation: School of Life Sciences, Jawaharlal Nehru University, New Delhi, India ; Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, India.
authors.forename: Rajiv K
authors.initials: RK
authors.lastname: Saxena
authors.forename: Nitin
authors.initials: N
authors.lastname: Bhardwaj
authors.forename: Sumedha
authors.initials: S
authors.lastname: Sachar
authors.forename: Niti
authors.initials: N
authors.lastname: Puri
authors.forename: Sanjay
authors.initials: S
authors.lastname: Khandelwal
keywords: Double in vivo biotinylation; Erythrocyte aging; Erythrocyte removal; Mouse blood circulation